1. Field of the Invention
This invention relates to film processing apparatus and, more particularly, to a mechanism for unloading exposed film from a film cassette in a lighted area for splicing and subsequent processing.
2. Description of the Prior Art
Film splicers for joining individual lengths of film end-to-end are in common use in the film processing industry. Although such splicers greatly improve the efficiency of film processing in comparison to processing individual lengths of film, they nevertheless suffer from a variety of problems.
The initial problem is encountered at the front end of the splicer when the film is being unloaded from a cartridge. To prevent the film from being inadvertently exposed during the unloading process, the splicer must generally be operated in a darkroom. The darkroom is far from an ideal working environment so that the efficiency of the operating personnel is somewhat limited. Consequently, the capacity of such splicers is significantly lower than the capacity would be if the operators were permitted to work in a properly illuminated environment.
Recently "daylight" film splicers have entered the market which allow film to be loaded into a film splicer from a cassette in a properly illuminated environment. One such device is described in U.S. patent application Ser. No. 839,603, assigned to the assignee of this application. These recently developed daylight splicers are only semi-automatic so that they require relatively extensive manual manipulation of the cassette in order to load film into the splicer. The requirement of an operator for loading film into the splicer seriously reduces the throughput capacity of such splicers and introduces the possibility of error in film handling.
Another problem associated with conventional semi-automatic daylight splicers is their inability to adequately deal with film cassettes in which the film is incorrectly withdrawn from the cassette. Normally, as the backing strip is removed from the cassette thereby carrying the film from the cassette with it the backing strip protects the film from exposure to the daylight environment. However, a relatively small percentage of the cassettes which are unloaded become jammed so that the backing strip is removed from the cassette leaving the film behind. Another problem associated with an even smaller percentage of cassettes is that the film does not immediately exit the cassette but instead makes a complete loop within the cassette and exits the cassette backing strip so that the film is exposed to the daylight environment. The first above-mentioned problem is dealt with by segregating the cassette and subsequently processing it in a darkroom environment by conventional, non-automatic means. The second abovementioned problem is generally not dealt with in any satisfactory manner by conventional semi-automatic splicers so that a small percentage of film becomes inadvertently exposed.